In Vitro Culture of Immature Peanut ( Arachis spp.) Leaves: Morphogenesis and Plantlet Regeneration1,2

Abstract

Green immature leaflets (2-5 mm in length from shoots of germinated seeds or greenhouse grown plants) from species representing seven taxonomic sections of the genus Arachis (Ambinervosae, Arachis, Caulorhizae, Erectoides, Extranervosae, Rhizomatosae, and Triseminalae), were cultured aseptically, in vitro, on a medium composed of Murashige and Skoog salts, Gamborg's B5 vitamins, 0.8% Difco agar, and supplemented with 1 mg/L each of naphthaleneacetic acid and N-6 benzyladenine. Histological examination of the cultures revealed that the meristematic areas originated from epidermal cells. Embryoids and meristematic shoots developed after lysis of the surrounding cells. All species of Arachis tested produced callus. Genotypic differences for the production of callus, shoots, and roots were observed with cultivated peanuts. Organogenesis occurred in the leaflet cultures, and plants were recovered from sections Arachis and Extranervosae of the genus Arachis.